1. Field of the Invention
The present invention relates to a fitting structural body, a fitting and a flexible sheet inflatable/deflatable gate. In detail, the present invention relates to a fitting structural body structured to form a frame with fittings for gripping flexible sheets which are inflated by supplying a fluid and deflated by discharging a fluid and being mounted on a target structure; a fitting included in the fitting structural body; and a flexible sheet inflatable/deflatable gate mounted on the target structure using the fitting structural body.
2. Description of the Related Art
A culvert through which liquid and gas can flow may be provided on the inner surface thereof with a flexible sheet inflatable gate including flexible sheets (e.g. rubber sheets) At the flexible sheet inflatable gate, the flexible sheets inflate to obstruct the interior space of the culvert when a fluid (typically air) is supplied to the sheets so as to stop the flow of liquid or gas through the culvert. The flexible sheets deflate and recede in the culvert when a fluid is discharged from the sheets, so that liquid and gas can flow through the culvert.
FIG. 19 is a partially enlarged view of such flexible sheet inflatable gate provided in a culvert 118. The flexible sheet inflatable gate is arranged such that flexible sheets (a lower sheet 120 and an upper sheet 122) are mounted to the culvert 118, a target structure, using a fitting structural body 110.
The fitting structural body 110 includes a bottom wall fitting 124 disposed on a bottom wall 118L of the culvert 118, a slope fitting 126 disposed on a slope 118D, and a sidewall fitting 128 disposed on a sidewall 118S, corresponding to the shape of the culvert 118. The fittings 124, 126, 128 include respectively embedded fittings 124B, 126B and 128B fixed to the culvert 118 and pressing fittings 124H, 126H and 128H for gripping the flexible sheets (the lower sheet 120 and the upper sheet 122) between the embedded fittings 124B, 126B and 128B.
In mounting the structural body 110, the lower sheet 120 and the upper sheet 122 are placed in order on the embedded fittings 124B, 126B and 128B fixed to the culvert 118. Then, the pressing fitting 126H of the slope fitting 126 is mounted. Finally the pressing fitting 124H of the bottom wall fitting 124 and the pressing fittings 128H of the sidewall fitting 128 are mounted slantly as an arrow A (toward corners 130 and 132 of the culvert 118). Mounting in this order that works at a corner portion of the culvert (in the vicinity of the slope 118D) whose work area is narrower are done before those in the vicinity of the bottom wall 118L and the sidewall 118S whose work area is broader improves the operational efficiency.
The pressing fittings 124H, 126H and 128H are formed with a minus tolerance in view of practical construction since the culvert 118 is a constructed object having a large tolerance. Thus, in the above mounting condition, a significantly large gap may appear for example between the pressing fitting 124H of the bottom wall fitting 124 and the pressing fitting 126H of the slope fitting 126 (that is, at the corner portion 130).
On the other hand, an analysis such as three-dimensional FEM analysis has found that the tension at the time of inflating of the upper sheet 122 becomes large in the vicinity of the corner portions 130 and 132 and that the tension reaches the largest peak especially in the vicinity of the corner 130. Therefore, edge portions 134 at the corner portions 130 and 132 are arranged to have a curvature (roundishness) in a finishing process in order to avoid damages (e.g. holes) on inflating the upper sheet 122. The edge portion 134, however, easily become acute even in such arrangement with the roundishness due to its three-dimensional shape, so that it is still likely to damage the upper sheet 122.
In view of the above, an object of the invention is to obtain a fitting structural body, which would not damage flexible sheets; fittings included in the fitting structural body; and a flexible sheet inflatable gate mounted on a target structure using the fitting structural body.
A first aspect of the invention is that a fitting structural body structured to form a frame as a whole using a plurality of fittings for gripping a flexible sheet inflatable by supplying a fluid and deflatable by discharging the fluid and being fixed to the target structure, wherein the above fittings on the both sides of a non-linear part formed along a longitudinal side of the frame, are unified.
That is, a fitting structural body structured to form a shape of frame using fittings is fixed to the target structure and grips a flexible sheet, so that the flexible sheet is mounted on the target structure. The flexible sheet inflates or deflates by supplying or discharging a fluid to or from the flexible sheet so as to close or open a culvert or river.
The fitting structural body includes the non-linear part formed along a longitudinal side of the frame so that the fitting structural body can be formed corresponding to the target structure.
Further, the fittings are unified on the both sides of the non-linear part. Thus, no gaps at the non-linear part exist and no acute portions would contact with the flexible sheet. Therefore, the flexible sheet is not damaged even when the large tension acts on the flexible sheet at the non-linear part.
A second aspect of the invention is fittings included in the fitting structural body in the first aspect, provided at the non-linear part formed along a longitudinal side of the above-mentioned frame, and are unified at the both sides of the above non-linear part.
That is, the fitting structural body in the first aspect can be structured using the fittings in the second aspect. In the fittings in the second aspect, there are no gaps at the non-linear part, and no acute portions would contact with the flexible sheet and the flexible sheet would not be damaged.
In the second aspect of the invention, a specific structure for unifying the fittings on the both sides of the non-linear part is not particularly limited, but may be unified preferably by welding fitting elements, which are formed separate bodies so as to form the both sides of the above-mentioned non-linear part. More preferably, the fittings may be unified on the both sides of the non-linear part by cutting an elongated member, which is elongated beforehand longer in a longitudinal direction of the frame than the length of the fittings included in the above-mentioned fitting structural body, so that the elongated member is formed to correspond to the above-mentioned non-linear part.
Especially, the shape of the fittings may be individually different since the target structure on which the fittings are mounted often varies in the shape, size, angle and others. Consequently, many molds are needed when the fittings are manufactured using a mold, and may result in a high manufacturing cost. In contrast, in manufacturing the fittings by hot extruding, for example, the degree of freedom in the shape and dimension is high, and the fittings can be manufactured at a low cost. Thus, as in the present invention, the fittings are unified preferably by welding fitting elements, which have been formed into separate bodies, so that the fittings in the second aspect of the invention can be manufactured at a low cost.
In the present invention, the above-mentioned non-linear part of the aforesaid fittings is preferably processed so as to have a curvature in a view along a longitudinal side of the frame.
Therefore, damage of a flexible sheet can be avoided more reliably.
In the fittings according to the invention, a radius of curvature obtained by processing the non-linear part is preferably within a range from 50 mm to 1800 mm, for example, but not particularly limited to the above so long as the flexible sheet can be prevented from being damaged. Setting the radius at 50 mm or smaller can certainly prevent the flexible sheet from being damaged. When the radius is 1800 mm or smaller, the fittings can be prevented from being excessively enlarged in size or thickness.
In the present invention, anchor bolt inserting holes into which anchor bolts are inserted and which are provided in the target structure, are formed in any of the above-mentioned fittings.
Thus, comparing with the fittings in which only one anchor bolt inserting hole is formed, the fittings according to the invention can grip the flexible sheets with a greater power.
In the present invention, more preferably, all of the above-mentioned anchor bolt inserting holes are arranged in parallel in the fittings.
That is, anchor bolt inserting holes arranged not in parallel cause a power acting on the anchor bolts in the direction such that the space between the inserting holes would be enlarged (or narrowed, depending on the case) as nuts are screwed on the anchor bolts. Then, the nuts cannot be enough screwed due to the power, and thus a large tightening power may not be obtained. In contrast, a parallel arrangement enables the nuts to be sufficiently screwed, so that a greater tightening power can be obtained.
In the present invention, more preferably, the fittings are formed symmetrically in relation to a symmetric axis line passing through the above-mentioned linear part and that the above-mentioned anchor bolt inserting holes are provided in the positions symmetric in relation to the symmetric axis line.
Such arrangement of the fittings enables fittings included in one fitting structural body to be common.
In the present invention, the anchor bolt inserting holes of the above-mentioned fittings are preferably formed symmetrically in relation to a symmetric axis line passing through a center point of a corner portion in the above-mentioned fitting structural body.
Therefore, manufacturing processes of the respective fittings located on the both sides of the corner portion can be partially (preferably, all) used in common.
In the present invention, more preferably, at least one of the above-mentioned anchor bolt inserting holes is an elongated hole.
According to the above, the work efficiency in screwing an anchor bolt to grip the flexible sheets is improved.
In the present invention, more preferably, in the fitting structural body of the first aspect, which includes the above-mentioned fittings, a part contacting with adjacent fittings to the above-mentioned fittings is inclined in relation to a fixing direction so as to press the adjacent fittings against the above-mentioned structure for mounting.
That is, in the fitting structural body, the fittings of the second aspect described above press the adjacent fittings against the target structure. Accordingly, the adjacent fittings can be prevented from rising advertently.
In the present invention, more preferably, in the fitting structural body of the first aspect, which includes the above fittings, among fittings including the fittings in the second aspect, relatively upper fittings press relatively lower fittings adjacent to the upper fittings against the target structure, with the fittings fixed to the target structure.
Thus, by mounting (and tightening bolts of) the fittings in order from a lower place to an adjacent upper place to grip flexible sheets, the fittings can be easily mounted on the target structure. In this case, the flexible sheets are gripped in order in one direction. Thus, it is possible to minimize gaps and looseness in mounting, so that precise mounting can be achieved.
In the present invention, more preferably, in the fitting structural body in the first aspect, which includes the above fittings, among fittings including the fittings in the second aspect, there is a gap formed between at least one of the fittings and at least one of adjacent fittings to the fittings.
Such predetermined gap between the fittings adjacent each other improves the work efficiency in mounting flexible sheets to the target structure.
A third aspect of the present invention is a flexible sheet inflatable and deflatable gate comprising the fitting structural body and flexible sheets mounted on the target structure using the fitting structural body.
The flexible sheets can be prevented from being damaged since the flexible sheets are mounted on the target structure using the fitting structural body, as described above.
When the flexible sheets are mounted on the target structure, a flexible sheet inflatable gate is formed, and supplying or discharging a fluid can close or open the interior space of the target structure (e.g. a culvert or a dam for a river).